The present invention relates to an imaging-plate-type X-ray diffraction apparatus, and more particularly, to a space-efficient imaging-plate-type X-ray diffraction apparatus featuring a broad exposure area, high speed, high resolution, and convenient design for use.
Generally, in analysis of crystal structures of organic and inorganic substances, a single crystal of a substance to be analyzed is formed and subjected to X-ray diffraction measurement.
However, future research efforts will require development of apparatus capable of measuring data at high speed and resolution. For example, there is need for use of not only Mo (molybdenum) Kxcex1 rays (wavelength: 0.710 angstroms) but also Cu (copper) Kxcex1 rays (wavelength: 1.542 angstroms) in measurement by a single X-ray diffraction apparatus.
In order to meet such a need, the following types of apparatus for analyzing the structure of a single crystal by means of X-rays have been developed.
(1) An automatic X-ray single-crystal analyzer capable of measuring three-dimensional spots. The automatic X-ray single-crystal analyzer includes an X-ray generator, a 4-axis goniometer, a scintillation counter mounted on the 20-axis of the goniometer, and a computer system for processing diffraction data.
The automatic X-ray single-crystal analyzer can collect every X-ray diffraction datum of a sample, but occupies a large space and needs 3 to 4 days to collect all X-ray diffraction data of a sample because of measurement of three-dimensional spots.
(2) An imaging-plate-type X-ray diffraction apparatus including a cylindrical imaging plate which is disposed horizontally so as to acquire X-ray diffraction data simultaneously to thereby shorten time required to collect X-ray diffraction data.
This imaging-plate-type X-ray diffraction apparatus contributes greatly to the shortening of time required for collection of X-ray diffraction data. However, the 2xcex8 goniometry range of the apparatus is xc2x160 degrees; i.e., the apparatus is dedicated to measurement through use of Mo Kxcex1 rays (wavelength: 0.710 angstroms). When Cu Kxcex1 rays (wavelength: 1.542 angstroms) are used, a 2xcex8 goniometry range of at least 0 to 140 degrees is required. In order to acquire this 2xcex8 range, space for access to a crystal must be narrowed significantly, thereby affecting convenience of use.
Thus, in order to carry out measurement through use of Mo Kxcex1 rays (wavelength: 0.710 angstroms) as well as Cu Kxcex1 rays (wavelength: 1.542 angstroms), a user has no choice but to endure a long time taken for the collection of data by use of the apparatus described above in (1), or to sacrifice convenience of use.
The apparatus described above in (2) is of the horizontal type, involving a problem in that the width is large.
An object of the present invention is to solve the above-mentioned problems and to provide a space-efficient imaging-plate-type X-ray diffraction apparatus featuring an expanded 2xcex8 goniometry range, high speed, high resolution, and convenient design for use.
To achieve the above object, the present invention provides an imaging-plate-type X-ray diffraction apparatus as described below.
An imaging-plate-type X-ray diffraction apparatus comprises means for causing a set single-crystal sample to diffract X-rays, the means comprising an X-ray optical system and a goniometer, the sample being set on the goniometer; a cylindrical imaging plate disposed vertically so as to record X-rays diffracted by the sample, and covering a 2xcex8 goniometry range of xe2x88x9260xc2x0 to +144xc2x0; transfer means for transferring the cylindrical imaging plate vertically; and a rotary reader disposed so as to be coaxial with the transferred cylindrical imaging plate and adapted to read data of diffracted X-rays from an inner cylindrical surface of the cylindrical imaging plate.
In a preferred embodiment of the imaging-plate-type X-ray diffraction apparatus as described above, the goniometer is disposed at a position located inside the cylindrical imaging plate and corresponding to a lower portion of the cylindrical imaging plate, without mechanically interfering with the X-ray optical system and the cylindrical imaging plate, such that an axis of the sample is positioned vertically.
In the imaging-plate-type X-ray diffraction apparatus as described above in [1], the radiated X-rays are preferably Cu Kxcex1 rays.